Connector with fusible material



March 29, 196e Filed July 23, 1962 J. D. WETMORE CONNECTOR WITH IFUSIBLEv MATERIAL 5 Sheets-Sheet l arme/V56 March 29, 1966 J. D.. WETMORE 3,243,211

CONNECTOR WITH FUSIBLE MATERIAL Filed July 23, 1962 S'Sheets-Sheet 2 Y Il INVENTOR. f. Jafa/v mmf Wim/@e5 BY fi-gm March 29, 19.66 J. D. WETMORE CONNECTOR WITH FUSIBLE MATERIAL 5 Sheets-Sheet 5 Filed July 23, 1962 United States Patent O CONNECTOR WITH FUSIBLE MATERIAL Judson Douglas Wetmore, San Diego, Calif., assigner to Raychem Corporation, Redwood City, Calif., a corporation of California p Filed July 23, 1962, Ser. No. 211,747

Claims. (Cl. 287-78) The present invention relates to articles which are capable of changing shape and which contain a fusible insert. The present invention includes within its scope articles in which the fusible insert operates to restrain the recoverable portion of the article against recovery and articles in which the fusible insert does not restrain the recoverable portion of the article against recovery.

It has long been known that recoverable articles are useful for covering other articles. For example, elastic rubber sleeves have often been used to cover cylindrical articles merely by choosing a sleeve which, in its relaxed condition, has a diameter less than that of the article to be covered. The tendency of the sleeve to retract when it has been expanded and placed over the article results in Ia covering for the article which, for some few purposes, is satisfactory. Heat recoverable articles have also been used in a somewhat similar manner. An example of such a heat recoverable member is found in Patent 2,027,962, issued January 14, 1936 to Currie.

However, the recoverable articles known to the prior art have been found to be completely unsatisfactory in the many instances when a strong and impervious bond between the recoverable article and the article which is to be covered is desired. For example, it is common practice to laminate -an insulating covering over electrical components such as conductors. The insulating material must, of course, be securely bonded to the conductor in order to protect the conductor from water or air or other media with which it may come into contact. Furthermore, it is also highly important that there -be no air spaces between the covering and the conductor. The occurrence of air spaces is particularly troublesome where the insulating material is applied to an element having an irregular surface, such as a plurality if wires which have been twisted together to form a cable or braided structure. Thus, as is well known to those skilled in the art, there has been a long standing need for coverings which are easy to apply, such as recoverable articles, and yet are capable of forming a secure, intimate, impervious bond with the article which is covered.

The present invention satises this long standing need in a surprisingly simple and economical manner.

One of the principal objects of the present invention is to provide a recoverable article capable of being laminated or otherwise united with lanother article in such a manner that a secure, intimate and impervious bond is formed and the process of so doing.

Another object of the present invention is to provide a heat recoverable article capable of being laminated or otherwise united with another article in such a manner that a secure, intimate and impervious bond is formed and the process of so doing.

A further object of the present invention is to provide a heat recoverable article having elastic memory which is capable of being laminated or otherwise united with another articlein such a manner that a secure, intimate and impervious bond is formed and the process of so doing.

It is still another object of the present invention to provide an article and process for forming a laminated or otherwise united insulating covering which is securely, intimately and imperviously bonded to electrical elements.

Mnce

It is ia 4funther object 'of the present invention to provide a recoverable article having a fusible insert and processes for using this article.

Other objects and advantages of the present invention will become apparent from the following detailed descrpition, when read in conjunction with the drawings, of preferred embodiments of the present invention.

Briey, the present invention comprises, in part, a recoverable article which is provided with a fusible insert. The recoverable articles of the present invention may comprise elastic materials which have been stretched and yare held in the stretched condition, heat recoverable articles, such as articles made from materials having the property of plastic memory, or the like. The fusible inserts of the present invention may comprise any suitable fusible material, e.g., thermoplastics such as polyolenes. Furthermore, the word insert, as used in the description of the present invention, contemplates any member which is positioned suchV that it will be interposed between the recoverable material and an article with which the recoverable material is to be la-minated or otherwise united. For example, in those instances where a tubular article is to be provided with an inner lining comprising the recoverable material, the insert comprises a fusible outer layer provided von the outer surface of the recoverable material. The process of the present invention comprises forming the recoverable material such that it has a dimension different from that of the article to which it is to be laminated or otherwise united and such that it has the property of being capable of changing its dimensions. The recoverable material is then provided with fusible material which is positioned such that it will be interposed between the recoverable material and the article to which it is to be laminated or otherwise united. The fusible insert is preferably in abutting relation to the recoverable member. The article of he present invention is then positioned with relation to the article to which it is to be laminated or otherwise united in such relation that change in the dimensions of the recoverable material will cause it to urge the fusible member toward the article to which it is to be attached and cause it to become bonded thereto. The article of the present in-` vention is then subjected to suicient heat to cause the fusible material to become iluid. -Iu a preferred embodiment of the present invention, where recoverable articles having the property of elastic memory are employed, the application of heat also causes the recoverable material to exercise this property. Furthermore, the preferred embodiment of this invention comprises a recoverable member which is capable of changing its dimensions in response to the application of heat at a given temperature and a fusible member which will become fluid at the same temperature.

In the drawings:

FIGURE 1 illustrates an embodiment of the article of the present invention in which the article has a tubular shape.

FIGURE 2 illustrates another embodiment of the present invention in which the recoverable member is a split cylinder.

FIGURE 3 illustrates still another embodiment of the present invention wherein the recoverable member is mounted on a coil spring.

FIGURE 4 illustrates another embodiment of the present invention wherein the recoverable member is closed at one end.

FIGURE 5 illustrates another embodiment of the present invention wherein the recoverable member is closed at one end and contains a ball of solder.

FIGURE 6 illustrates another embodiment of the present invention wherein the recoverable member is closed at -one end and contains a ball of solder and electric conductors.

FIGURES 7 and 8 illustrate embodiments of the present invention which are similar to the embodiments illustrated in FIGURES and 6, "respectively, except that the recoverablemember is-open at both ends.

FIGURE 9 illustrates a'n `embodiment of the kpresent invention wherein vthe `recoverable member comprises a spirally wrapped'article. l FIGURE fl() lillustrates-an embodiment of the present invention whereinthe v'conductors encapsulated by the article `of the present invention have been crimped. IFIGURE l11 illustrates an embodiment of the present invention wherein one yconductoriis spirally wound about another before the conductors areispliced.

FIGURE 12 illustrates an embodiment of the present invention wherein 'the kfusible Amember comprises a longitudinally perforated cylinder.

FIGURES 13A-D illustrate a preferred embodiment of the present invention lwherein lthe fusible lmember functions asia dam for solder.

Referring now to the drawings, FIGURE l illustrates a preferred embodiment of Athe present invention wherein the r'e'coverablefmember'l and fusible insert 2 are tubular in shape. Ina `preferred embodiment of the present invention, the recoverable material is a yheat recoverable material having the property of elastic memory, such as the materials disclosed in U.S. 'Patent No. 2,027,962. Whenfthistypeof `recoverable material is used, the 'fusible insert may comprise `virtually any material capable of being rendered flow'able by the application of heat. For example, conventional thermoplastic materials such 'as polyolefines v`(polyethylene, polypropylene, etc), 'polyamides (e;g., nylon), polyesters (e.g., polyethylene tereplithalate cellulose acetate), and-other similar materials. Itis, however, to ybe understood that the present invention is-notlimited-to the use of conventionalthermoplasticsas the fusible-insert. Rather, -thermosetting materials such as epoxy "resins, pOlyurethaneS, vphenol-aldehyde lcondensation products, etc., frnay also be used. Still further, it lis possible to use, in ycombination with the recoverable material certain materials `which would -not operate vin precisely the 4same manner "as -fusible materials, such as insulating or conductive grease's or heat catalyzed adhesivesfand'the'like.

`In the preferred 'embodiment wherein the Vrecoverable member isla-heat recoverable member :having elasticmemory properties,the 'fusible insert 2 'maybe combined 'with the recoverable material 1 in any `suitable manner. For example, the fusible material maybe applied to -Vthe recoverable material Vas a coating or Athe fusible insert may be formed `into a predetermined size 'such that it will be held by the recoverable `member. simply by frictional forces, ie., by a 4force fit. It will be obvious to those skilledin the art that, when practicing the present invention in accordance with this preferred embodiment, the recoverable member must,)in^general, be deformed `in such a manner that-it-possesses elastic memory properties before the fusible insert is added. There are several well lcnownmethods 4according to which recoverable materials may be deformed Vsuch'tha't they possess the 'property of elastic memory. One such method is clearly disclosed in ULS. Patent No. 2,027,962, whichis `incorporated hercin by reference. Asdisclosed inthis patent, such materials are independently dimensionally heat unstable, Le., capable of 'changing dimension to assume a heat stable condition upon the 'applicationof heat alone. Thus, un-

like that embodiment of the present invention `illustrated regardless of whether the fusible member 2 is present. Any such method may be used in the practice of the present invention. Ordinarily, the fusible insert is added to the recoverable material after the recoverable material has been caused to assume dimensions in which it has the property of elastic memory. However, the fusible insert of the present invention may be added to the recoverable member in particulate or powder form. When the article Vof the present invention is heated, the fusible p articulate material ilows to form an impervious coating. When the fusible material is added to the recoverable material in particulate form, the addition may be performed before or lafter the recoverable `material is deformedsuch that vit possesses the property of elastic memory. Thus, the use of particulate fusible material has the advantage that the article of the present invention may be assembled without causing the recoverable material to assume any given dimensions. deformed by the user to the precise `extent required by 'a given 'purpose for which the article is to be used.

In another embodiment of the present invention, the recoverable material 1may comprise an elastic material such as natural or synthetic rubber. In this embodiment, the fusible insert must possess sufficient structural strength that it is able to withstand the compressive forces exerted by the recoverable material after it has been distended. According'to this embodiment, the vfusible insert is iirst formed to a size different from that of the article to which the article of the present invention is to be laminated or otherwise united. For example, as illustrated in FIGURE l, elastic material 1, which has a diameter smaller than that of insert 2 when it is in the relaxed state, is `stretched over insert 2. The combined recoverable material i1 and insert 2 may then be placed over an article to be encapsulated, 'such as an electric'condui't or the like, which is of a diameter substantially the same as, or somewhat larger than, the original relaxeddiarneter of the recoverable material 1. The encapsulation is accomplished'by kthe application of sutlcient lheat to `fuse or break down the crystalline structure of insert V2;, thereby causing insert 2 lto -lose its rigidity and permitting lthe recoverable material 1 to contract elastically to approachits original dimension. The 'result is a highly effective bonding of recoverable 'material 1 tothe encapsulated article. This method may be used for true encapsulation inthe sense of fusing the insert 2 to the member yto be encapsulated, or may function simply to produce -a heat shrinkable elastic tube wherein the rigid insert is used only for the purpose of temporarily maintaining the recoverable vmaterial in its expanded condition.

yIn the embodiment of the present invention illustrated in FIGUREZ, the recoverable material is a split-cylinder type spring 3 which is Aheld under tension -by rigid fusible insert -4. `Sp1-ing f3 is illustrated as being made from metal, but it is to be understood that spring 3 may comprise other suitable mate'rials such as `plastic or hard rubber. Furthermore, itis also to ybe understood that the relation of members 3 and 4 maybe reversed such that rigid fusible member 4 surrounds spring 3 and holds it under tension. The function `of this embodimentcof the .present invention `is essentially the same as that previously described with `respect to the use of a stretched elastic 4material as'the recoverable material.

FIGURE 3 illustrates an embodiment ofthe present invention wherein recoverable material 5, which has a circular horizontal crosssection and `is provided with fusible material 6 which is suitably bonded, eg., by adhesive, thereto, holds coil spring 7 in compression. In this embodiment, recoverable material 5 comprises va material possessing the property of elastic memory. When the assembly illustrated in FIGURE 5 is heated, the recoverable material 5 releases the compressive forces which it exerts fon spring 7. Spring 7 then 'functions to urge fusible portions '6 into contact with the article with which the assembly is to be united.

The assembled article may then ber FIGURES 4-6 illustrate embodiments vof thepresent invention in which the recoverable material 8 has a closed end. This closed end may be formed by sealing, by appropriate means, one end of a tubular member, or may be formed simply by molding a thimble shaped article. The articles illustrated in FIGURES 4-6 are particularly useful for terminating electrical conduits.

The embodiment illustrated in FIGURE 4 is essentially the same as that illustrated in FIGURE 1, with the exception that one end of the recoverable member 8, which surrounds fusible member 9, is closed.

In the embodiment illustrated in FIGURE 5, a ball of solder and llux is positioned within fusible member 9. Thus, when the assembly illustrated in FIGURE 5 is heated, not only is fusible member 9 caused to fuse and recoverable member 8 caused to contract to a smaller diameter, but the ball of solder and ux 10 is also caused to fuse. The solder thus supplements f-usible member 9 as an encapsulating material.

In FIGURE 6, recoverable member 8 is illustrated as it would appear with fusible member 9, ball of solder ii 10 and Wires 11 inserted therein.

The embodiment illustrated in FIGURE 7 is essentially the same as that illustrated in FIGURE 5 with the exception that recoverable member 12 is open at both ends.

The embodiment illustrated in FIGURE 8 is similar to that illustrated in FIGURE 7, with the addition that" a rigid sleeve 13,'preferably comprising metal, is inserted within fusible member 9. It is preferred that rigid member 13 have an axial dimension less than that of recoverable member 12 and fusible member 9. Thus, when heat is applied to this assembly, the recoverable member contracts down around the sides of rigid member 13. It is to be understood that solder 10 may be omitted from this embodiment. p n u A Since the articles of the present invention are particularly suitable for splicing and terminating the ends of electrical conduits, the procedure for so using the articles of the present invention will be described in some detai1.

The` embodiment illustrated in FIGURE 6 may be used for making a waterproof soldered splice on plastic insulated wire ends. The splice can be accomplished without` stripping the wire ends, twisting the wire ends,V flexing the wire ends, crimping the wire ends together vor other commonly used methods. The fusible member 9 of the article of the present invention should be a material which is capable of fusing or bondingto the plastic insulation onV the wire. As shown in FIGURE 6, the recoverable article is provided with solder and, if desired, a uxing material. The unstripped wire ends 11 are pressed against the top of the solder. Heat is then applied tothe assembly. High frequency induction heating has been foundY suitable in those cases where solder is used. When the heat is applied, the recoverable member 8 contracts to encapsulate or surround the fusible material 9 which is melted by the heat. The heat also causes the insulation on the ywires to migrate away fromV the'V ends thereof, thereby exposing the wires.

along the axis of the4 tube in order to form a `butt type"- or parallel type junction.

As illustrated in FIGURES 1 and 4, the soldermay be omitted where it is not4 necessary, eg., where soldered wires are being covered.` Furthermore, as illustrated in FIGURE7, the sleeve 13 may be omitted if the structural strength which it imparts is not required.V

In `those instances where the recoverable member of the article of the present invention is to be tubular in shape, the tube .may be extruded, molded or fabricatedI The heat further causes the solder to fuse around the exposed wires. Upon coolfusible member 24 will become flowable.

6 from a flat`sheet of material simply by rolling it into a tube and suitably sealing the seam. Where greater compressive force is desired than that which may be :obtained with a single layer of recoverable material, the flat sheet may be rolled into a tube in such a manner that a series of spirally wound layers are formed as illustrated in FIGURE 9. The compressive forces exerted by the spirally wound layers 14 on fusible member 15 are substantially greater than those exerted by a single layer of recoverable material.

In those instances where the article of the present invention is used to splice electric conductors and in which it is desired to omit the solder, eg., the embodiments illustrated in FIGURES l and 4, it has been found desirable, as illustrated in FIGURE 10, to apply crimping force to the spliced conductors 16 and 17 at the point where the exposed conductors are in contact with each other. The crimping assures that an effective connection is made between the conductors. The crimping may, of course, be performed either before or after the article of the present invention comprising fusible member 18 and recoverable member 19, is used to splice the connectors.

As illustrated in FIGURE 11, particularly where a splice is to be made without the use of solder, the insulation may be stripped from one of the conductors 20 for suicient length to expose a portion of the conductory which is long enough to be spirally wrapped around the exposed portion of the other conductor 21. After the spiral winding is performed, the article of the present invention, comprising fusible member 22 and recoverable member 23may then be used to effect the splice in any of the manners described herein.

Where a plurality of conductors are to be spliced independently, or where a plurality of articles are to be independently encapsulated, the embodiment of the present invention illustrated in FIGURE 12 may be used. In this embodiment, fusible member 24 is provided with a plurality of perforations 25. When heat is applied to the article, recoverable member l26 will contract and Thus, individual articles which are to be spliced or encapsulated may be positioned in perforations 25 and heat then applied to assembly. This embodiment of the present invention has the distinct advantage that the possibility of voids or air spaces occurring between the articles positioned in perforations 25 issubstantially eliminated.

It will be readily apparent to those skilled in the art that the devices .of the present invention have numerous and varied uses. For example, they may be used to join two or more pieces of metal and/ or plastic together, for joining two or more cylindrical or square pieces of tubing together, for joining two or more pieces of tubing or rod or combinations thereof together, for the application of casters to chair legs, and for sealing bottle caps or for sealing covers on containers. Furthermore, these articles may be used for lamination in general, for connection of any two similarly shaped objects, for forming a moisture proof covering on one or more objects, for making a chemical resistant covering for one or more objects, as

`well as for splicing, encapsulating, etc., of electrical elements. j

vAs illustrated in FIGURES 13A-D, the fusible insert of the present invention may perform multiple functions.

`According to this embodiment of the invention, recoverable member 27 is first molded or otherwise formed into the shape illustrated in 13A such that it is provided with recessed portion 28. The article is then deformed as illustrated in FIGURE 13B so as to impart elastic memory properties thereto according to any of the well known processes for so doing such as those which have previously been described. Article 27 is then provided with fusible insert 29 and solder 30 as illustrated in FIGURE 13C. Electrical conductors 31 having insulat- 4ing covering 32 thereon are then inserted into the interior of article 27 as illustrated in FIGURE 13D. Heat is thenapplied to this assembly which causes recoverable article 27 to return to its original configuration (illustrated in FIGURE 13A), and which also causes .fusible insert 29 and solder 30 to become uid. The heat also causes insulation 32 tormigrateraway from the ends of conductors 3i which'migration is illustra-tedafter partial completion in FIGURE 13D. i Since the ends of conductors 31 are located in recessed area 28, the contraction of recoverable material 27 will cause fusiblewinsert 29 to come into contact with insulation 32 without causing recoverable member 27 to come intocontact with conductors 31'. Furthermore, since the density of solder 30 is greater than that of insulation 32, the solder wilbl tend to force the insulation away from the ends of lconductors 31.. rlfhe fusible material 29, after the application of heat, forms a darn around conductors 31 which prevents the escape of solder 30 and assures an effective splice of conductors 31. y u u v y i It will be obvious to those skilled in the art that many variations of the fundamental concepts previously described are possible without departing from the scope of the present invention. For example,V the articles of the present invention may have any desired configuration. The configuration of the articles of the present invention will, in most cases, be determined by the shaperof the articles to which they are yto be laminated or otherwise united. Furthermore, although the foregoing description has described in [most detail those embodiments in which the recoverable member is caused to as'sumea final dimension less than that which it possesses in the recoverable state, itis to be understood that the present invention is equally applicable to recoverable members which expand rather than contract. vFor example, by providing a tubular recoverable member with a fusible member which surrounds the recoverable member, an larticle which is particularly suitable for the lining of tubular members such as pipes is produced. The expandable recoverable article of the present invention is, for example, positioned within a pipe which it is desired to line, andl heat is applied to .the` article. lThe article of the present invention is thus caused to expand in diameter and the fusible material is caused to become ilowable.` The resultant product isa pipewhich has been provided witha` securely bonded liningfof the recoverable material.

The recoverable member o f the present invention may comprise an irradiated or chemically cross-linked polymeric material; Polyolefnesuare a particularly suitable type-of polymeric material for this type of recoverable material. They polymericmaterial is first extruded "ori otherwise molded into a desirable shape. The polymeric material' is then cross-linked or given. the propertiesV of cross-linked material by exposure to ultraviolet-radiation or high energy radiation, ev.g.` a high energy electron beam, or byJ chemical means, e.g., yperoxides when polyolensareused. The cross-linked polymeric material is then heated and deformed, andthenu locked` in that condition by quenching or other suitable cooling means or, inthe alternative, the same process can be accomplished at room temperature b-yuusing greater force to deform the polymeric material. The lefo'r'med material will retain its shape almost indefinitely until exposed to'aV temperature abover its Ic1'ystalline melting temperature, eg., approximately250 F. in the casev of polyethylene.

Other materials which'- have been` found to'be' particularly satisfactory for use in the-.present invention are heat recoverable elastomeric materials and" polytet'rafluo'roethylene. In' general, anyA material possessing the prop'- er'ty of'elastic memory' (sometimes referred toas'plasticv memory), Aas Well as otl'ierfre'cofveiable materials,` such as elastic ory rubbery. materials, may 'b'used'in the' practiceA of the present invention;

It will be' apparent to" those skilled 'in the an that the Furthermore, the recovery of `the recoverable member may be controlled by the insertion of rigid members in the articles ofthe present invention in order to cause the recoverable materailto recover in a desired manner. For example, a coil spring may be `embedded in either the recoverable member 0r the fusible member or attached merely by the tension exerted by the spring itself such that the recoverable material will cause the spring tobecome elongated, `compressed or a combination of both, Still further, therecovery of the recoverable member may be controlledby differential heating such that one portion of the member will undergoa greater change in dimension than another portion. The vheatingdescribed in the present application may `be a positive application of heat, cpg., radiation heating, induction heating, electric resistance heating, heat generated byvan exothermicl reaction, etc., or may constit ute the exposure of refrigerated materials to atmospheric, or lower, temperatures". For example, a crystalline elastomeric material could be distended, held in the distended state and subjected to refrigeration lto freeze it in itsdistended state. This ar.- ticle could then be provided with a fusible insert which would become fluid at, say, room temperature. Such an article would then operate according to the present invention merely by exposure to room temperature.

Still further, the fusible insert of the present invention may be such that it is capable of becoming uid at the same temperature ,as that` required to cause the recoverable member to changedimension, or it may be capable of becoming uid at either a higher or lower temperature than that required to cause the recoverable member to change, dimension. Where Vthe fusible material cornprises a thermosetting rnateriaLl the heat may also cause this; material to harden as well as causing it to become fluid.

The induction heating-.used in the practice of the present invention may be any type of high frequency heating.

The articles of the present invention havepmany uses otherthan those previously described. v For example, the fusiblev materialI may function to cause a bond to Vbe formed, to fill voids, to; release a spring or other similar element, as dam to prevent the fiow of another fuid, etc.V The force exertedby the recoverablemember,mayfunction to move another object, to cause a securebonding, to release a diaphragm whichcloses or opens a conduit, etc,

Having fully described the present, invention, it is to be understood that itis not to be limited to'the specific details set forth, butI it' is of the full scope ofthe appended claims.

Ivclaim: u l i y 1. A tubular article having at least one open/endhthe Wall thereof comprisinga material which has been dimensionally changed from an original heat stable form Vto tiallyl preventing the passage of said fusibleY vmaterial beyond saidione end'whenv an externalmember is telescoped with theV means an'dlup'on the application` of heat sufficient to cause said dimensionally heat unstable material to change, dimension; v v

2. The article ofY claim 1" wherein said* means com-` prises a` separate secondi-member'comprising fusible material in abutting relation to said wall and positioned within the direction of dimensional change .ofV said; dirnen-V i sionally heat unstable Wall, said first member, having a viscosity whichA is low relative to theviscosity of said second member at ateinperature at which said dimen- SOHaUY'hGat unstable material undergoes" dimensional change,

3. The article of claim 1 wherein said rst member is solder.

4. The article of claim 2 wherein said rst member is solder.

5. The article of claim 2 wherein said second member comprises a ring of thermoplastic polymeric material.

6. The article of claim 1 wherein said wall comprises a crystalline polymericV material exhibiting elastomeric properties when heated to a temperature at least equal to its crystalline melting temperature.

7. The article of claim l-wherein said wall comprises a crosslinked polymer.

8. The article of claim 7 wherein said wall comprises a crosslinked polyolen.

9. The article of claim 1 wherein said wall comprises polytetrauoroethylene.

10. A tubular article having at least one open end, the wall thereof comprising a material which has been dimen sionally changed from an original heat stable form to an independently dimensionally heat unstable material capable of moving in the direction of its original form upon the application of heat alone, a rst member comprising fusible material in abutting relation to said wall and positioned within the direction of dimensional change of said dimensionally heat unstable wall, and dam means capable of dimensional change under heat positioned between said rst member and said one end for substantially preventing the passage of said fusible material beyond said one end when an external member is telescoped with said end and upon the application of heat sufficient to cause said d-imensionally heat unstable material to change dimension.

11. A tubular article having at least one open end, the Wall of said tubular article comprising a material which has been dimensionally changed from an original heat stable form to an independently dimensionally heat unstable material capable of moving in the direction of its original form upon the application of heat alone, said dimensionally heat unstable vmaterial comprising a crystalline polymeric material which exhibits elastomeric properties When heated to a temperature at least equal to its crystalline melting temperature, a mass of solder in abutting relation with said wall and within the direction of dimensional change of said dimensionally heat unstable material, said one end comprising means for dimensional change under heat in a direction substantially preventing the passage of said solder beyond said one end when an external member is telescoped with said end and upon the application of heat sufficient to cause said dimensionally heat unstable material to change dimension.

12. The article of claim 1 wherein said fusible material is in the form of a tube, the exterior wall of said tube being in contact with the interior wall of said article.

13. The article of claim 11 wherein said tubular article has a closed end.

14. The article of claim 11 wherein said wall comprises a crosslinked polymer.

15. The article of claim 11 wherein said wall comprises a crosslinked polyolen.

16. The article ofY claim`11 wherein said wall comprises polytetrauoroethylene.

17. An article having at least one open end and having ra tubular walll comprising a material which has been dimensionally changed from an original heat stable form to a dimensionally heat unstable material which is capable of moving in the direction of its original form upon the application of heat alone, a first member comprising fusible material in abutting relation with said wall and positioned within the direction of dimensional change of said wall, the dimensional stability of said wall being such that different portions thereof will undergo dimensional change to a different extent upon the application of heat forming means substantially preventing the passage of said fusible material beyond said one end when an external member is telescoped with said end.

18. A tubular article having at least one open end and having a wall comprising material which has been dimensionally changed from an original heat stable form to a dimensionally heat unstable material capable of moving in the direction of its original form upon the application of heat alone, a rigid member positioned kwithin the direction of dimensional change of said wall and forming means preventing recovery of a portion of said wall to its original form upon the application of heat, a member comprising fusible material positioned adjacent said rigid member and in such relation to said wall that upon the application of heat suicient to cause said dimensionally heat unstable material to change dimension the passage of said fusible material beyond said one end is substantially prevented when an external member is telescoped with said one end.

19. The article of claim 1 wherein said fusible material is thermosetting.

20. The article of claim 1 wherein a surface of said rst member is exposed and free to come into contact with an external member upon the application of heat suiicient to cause said dimensionally heat unstable material to change dimension.

References Cited by the Examiner UNITED STATES PATENTS 934,711 9/ 1909 Chapman 206-47 X 2,562,677 7/ 1951 Nolan 206-46 2,702,651 2/ 1955 Graham 220-35 2,790,285 4/ 1957 Pike et al 53-42 X 2,855,581 10/ 1958 Freedom 29-155.55 X 2,885,105 5/1959 Heyl et al 21S-38 2,941,911 6/1960 Kumnick et a1.

2,989,785 6/ 1961 Stahl 18-59 3,017,302 l/ 1962 Hultkrans.

3,022,543 2/1962 Baird et al.

3,037,529 6/ 1962 Hancik 138--109 3,040,385 6/1962 Folta 264-230 3,062,373 11/ 1962 Reynolds 206-65 3,071,819 1/1963 Harrison 18-59 3,087,610 4/ 1963 Kirkpatrick 206--65 3,130,260 4/1964 Gray 174-152 FOREIGN PATENTS 1,276,091 10/ 1960 France.

THERON E. CONDON, Primary Examiner.

MORRIS LIEBMAN, Examiner.

F. MARLOWE, M. L. RICE, Assistant Examiners. 

1. A TUBULAR ARTICLE HAVING AT LEAST ONE OPEN END, THE WALL THEREOF COMPRISING A MATERIAL WHICH HAS BEEN DIMENSIONALLY CHANGED FROM AN ORIGINAL HEAT STABLE FORM TO AN INDEPENDENTLY DIMENSIONALLY HEAT UNSTABLE MATERIAL CAPABLE OF MOVING IN THE DIRECTION OF ITS ORIGINAL FORM UPON THE APPLICATION OF HEAT ALONE, A FIRST MEMBER COMPRISING FUSIBLE MATERIAL IN ABUTTING RELATION TO THE HEAT UNSTABLE MATERIAL OF SAID WALL ANS POSITIONED WITHIN THE DIRECTION OF DIMENSIONAL CHANGE OF SAID DIMENSIONALLY HEAT UNSTABLE WALL, SAID ONE END COMPRISING MEANS FOR DIMENSIONAL CHANGE UNDER HEAT IN A DIRECTION SUBSTANTIALLY PREVENTING THE PASSAGE OF SAID FUSIBLE MATERIAL BEYOND SAID ONE END WHEN AN EXTERNAL MEMBER IS TELESCOPED WITH THE MEANS AND UPON THE APPLICATION OF HEAT SUFFICIENT TO CAUSE SAID DIMENSIONALLY HEAT UNSTABLE MATERIAL TO CHANGE DIMENSION. 